src/repositories/release.rs

   1 use std::fmt::Display;
   2 use std::io::{BufRead, BufReader};
   3
   4 use anyhow::{bail, format_err, Error};
   5
   6 /// The code names of Debian releases. Does not include `sid`.
   7 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
   8 pub enum DebianCodename {
   9     Lenny = 5,
  10     Squeeze,
  11     Wheezy,
  12     Jessie,
  13     Stretch,
  14     Buster,
  15     Bullseye,
  16     Bookworm,
  17     Trixie,
  18 }
  19
  20 impl DebianCodename {
  21     pub fn next(&self) -> Option<Self> {
  22         match (*self as u8 + 1).try_into() {
  23             Ok(codename) => Some(codename),
  24             Err(_) => None,
  25         }
  26     }
  27 }
  28
  29 impl TryFrom<&str> for DebianCodename {
  30     type Error = Error;
  31
  32     fn try_from(string: &str) -> Result<Self, Error> {
  33         match string {
  34             "lenny" => Ok(DebianCodename::Lenny),
  35             "squeeze" => Ok(DebianCodename::Squeeze),
  36             "wheezy" => Ok(DebianCodename::Wheezy),
  37             "jessie" => Ok(DebianCodename::Jessie),
  38             "stretch" => Ok(DebianCodename::Stretch),
  39             "buster" => Ok(DebianCodename::Buster),
  40             "bullseye" => Ok(DebianCodename::Bullseye),
  41             "bookworm" => Ok(DebianCodename::Bookworm),
  42             "trixie" => Ok(DebianCodename::Trixie),
  43             _ => bail!("unknown Debian code name '{}'", string),
  44         }
  45     }
  46 }
  47
  48 impl TryFrom<u8> for DebianCodename {
  49     type Error = Error;
  50
  51     fn try_from(number: u8) -> Result<Self, Error> {
  52         match number {
  53             5 => Ok(DebianCodename::Lenny),
  54             6 => Ok(DebianCodename::Squeeze),
  55             7 => Ok(DebianCodename::Wheezy),
  56             8 => Ok(DebianCodename::Jessie),
  57             9 => Ok(DebianCodename::Stretch),
  58             10 => Ok(DebianCodename::Buster),
  59             11 => Ok(DebianCodename::Bullseye),
  60             12 => Ok(DebianCodename::Bookworm),
  61             13 => Ok(DebianCodename::Trixie),
  62             _ => bail!("unknown Debian release number '{}'", number),
  63         }
  64     }
  65 }
  66
  67 impl Display for DebianCodename {
  68     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
  69         match self {
  70             DebianCodename::Lenny => write!(f, "lenny"),
  71             DebianCodename::Squeeze => write!(f, "squeeze"),
  72             DebianCodename::Wheezy => write!(f, "wheezy"),
  73             DebianCodename::Jessie => write!(f, "jessie"),
  74             DebianCodename::Stretch => write!(f, "stretch"),
  75             DebianCodename::Buster => write!(f, "buster"),
  76             DebianCodename::Bullseye => write!(f, "bullseye"),
  77             DebianCodename::Bookworm => write!(f, "bookworm"),
  78             DebianCodename::Trixie => write!(f, "trixie"),
  79         }
  80     }
  81 }
  82
  83 /// Read the `VERSION_CODENAME` from `/etc/os-release`.
  84 pub fn get_current_release_codename() -> Result<DebianCodename, Error> {
  85     let raw = std::fs::read("/etc/os-release")
  86         .map_err(|err| format_err!("unable to read '/etc/os-release' - {}", err))?;
  87
  88     let reader = BufReader::new(&*raw);
  89
  90     for line in reader.lines() {
  91         let line = line.map_err(|err| format_err!("unable to read '/etc/os-release' - {}", err))?;
  92
  93         if let Some(codename) = line.strip_prefix("VERSION_CODENAME=") {
  94             let codename = codename.trim_matches(&['"', '\''][..]);
  95             return codename.try_into();
  96         }
  97     }
  98
  99     bail!("unable to parse codename from '/etc/os-release'");
 100 }